The present work deals with the numerical analysis of phase change effects and choked flow on the rotordynamic coefficients of cryogenic annular seals. The analysis is based on the “bulk flow” equations, with the energy equation written for the total enthalpy, and uses an estimation of the speed of sound that is valid for single- or two-phase flow as well. The numerical treatment of choked flow conditions is validated by comparisons with the experimental data of Hendricks (1987, “Straight Cylindrical Seal for High-Performance Turbomachines,” NASA Technical Paper No. 1850) obtained for gaseous nitrogen. The static characteristics and the dynamic coefficients of an annular seal working with liquid or gaseous oxygen are then investigated numerically. The same seal was used in previous analyses performed by Hughes et al. (1978, “Phase Change in Liquid Face Seals,” ASME J. Lubr. Technol., 100, pp. 74–80), Beatty and Hughes (1987, “Turbulent Two-Phase Flow in Annular Seals,” ASLE Trans., 30(1), pp. 11–18), and Arauz and San Andrés (1998, “Analysis of Two Phase Flow in Cryogenic Damper Seals. Part I: Theoretical Model,” ASME J. Tribol., 120, pp. 221–227 and 1998, “Analysis of Two Phase Flow in Cryogenic Damper Seals. Part 2: Model Validation and Predictions,” ASME J. Tribol., 120, pp. 228–233). The flow in the seal is unchoked, and rotordynamic coefficients show variations, with the excitation frequency depending if the flow is all liquid, all gas, or a liquid-gas mixture. Finally, the pressure ratio and length of the previous seal are changed in order to promote flow choking in the exit section. The rotordynamic coefficients calculated in this case show a dependence on the excitation frequency that differ from the unchoked seal.

References

References
1.
Hughes
,
W. F.
,
Winowich
,
N. S.
,
Birchak
,
M. J.
, and
Kennedy
,
W. C.
,
1978
, “
Phase Change in Liquid Face Seals
,”
ASME J. Lubr. Technol.
,
100
, pp.
74
80
.10.1115/1.3453117
2.
Beatty
,
P. A.
, and
Hughes
,
W. F.
,
1987
, “
Turbulent Two-Phase Flow in Annular Seals
,”
ASLE Trans.
,
30
(
1
), pp.
11
18
.10.1080/05698198708981724
3.
Beatty
,
P. A.
, and
Hughes
,
W. F.
,
1990
, “
Stratified Two-Phase Flow in Annular Seals
,”
ASME J. Tribol.
,
112
(
2
), pp.
372
381
.10.1115/1.2920267
4.
Yasuna
,
J. A.
, and
Hughes
,
W. F.
,
1990
, “
A Continuous Boiling Model for Face Seals
,”
ASME J. Tribol.
,
112
, pp.
266
274
.10.1115/1.2920252
5.
Arauz
,
G. L.
, and
San Andrés
,
L.
,
1998
, “
Analysis of Two Phase Flow in Cryogenic Damper Seals. Part I: Theoretical Model
,”
ASME J. Tribol.
,
120
, pp.
221
227
.10.1115/1.2834413
6.
Arauz
,
G. L.
, and
San Andrés
,
L.
,
1998
,
Analysis of Two Phase Flow in Cryogenic Damper Seals. Part 2: Model Validation and Predictions
,”
ASME J. Tribol.
,
120
, pp.
228
233
.
7.
Hendricks
,
R. C.
,
1987
, “
Straight Cylindrical Seal for High-Performance Turbomachines
,”
NASA Technical Paper No.
1850
.
8.
Constantinescu
,
V. N.
,
1995
,
Laminar Viscous Flow
,
Springer-Verlag
,
Berlin
, Chap. 11, pp.
403
412
.
9.
Launder
,
B. E.
, and
Leschziner
,
M.
,
1978
, “
Flow in Finite-Width, Thrust Bearings Including Inertial Effects
,”
ASME J. Lubr. Technol.
,
100
(
3
), pp.
330
338
.10.1115/1.3453181
10.
Childs
,
D. W.
,
1993
,
Turbomachinery Rotordynamics: Phenomena, Modeling and Analysis
,
Wiley Interscience
,
New York
, Chap. 4, pp.
229
265
.
11.
San Andrés
,
L.
,
1991
, “
Analysis of Variable Fluid Properties, Turbulent Annular Seals
,”
ASME J. Tribol.
,
113
(
4
), pp.
694
702
.10.1115/1.2920681
12.
Hirs
,
G.
,
1973
, “
A Bulk Flow Theory for Turbulence in Lubricant Films
,”
ASME J. Lubr. Technol.
,
95
(
2
), pp.
137
146
.10.1115/1.3451752
13.
Colebrook
,
C. F.
,
1939
, “
Turbulent Flow in Pipes, With Particular Reference to the Transition Region Between the Smooth and Rough Pipe Laws
,”
J. Inst. Civ. Eng.
,
11
(
4
), pp.
133
156
.10.1680/ijoti.1939.13150
14.
Zirkelback
,
N.
, and
San Andrés
,
L.
,
1998
, “
Bulk-Flow Model for the Transition to Turbulence Regime in Annular Seals
,”
STLE Tribol. Trans.
,
39
(
4
), pp.
835
845
.10.1080/10402009608983602
15.
Arghir
,
M.
, and
Frêne
,
J.
,
2001
, “
A Triangle Based Finite Volume Method for the Integration of Lubrication's Incompressible Bulk Flow Equations
,”
ASME J. Tribol
,
123
(
1
), pp.
118
124
.10.1115/1.1326444
16.
Arghir
,
M.
, and
Frêne
,
J.
,
2011
, “
Numerical Solution of Lubrication's Compressible Bulk Flow Equations. Applications to Annular Gas Seals Analysis
,” Proceeding of International Gas Turbine & Aeroengine Congress & Exhibition,
New Orleans, LA
, Paper No. 2001-GT-117, pp.
1
9
.
17.
Arghir
,
M.
,
Defaye
,
C.
, and
Frêne
,
J.
,
2007
, “
The Lomakin Effect in Annular Gas Seals Under Choked Flow Conditions
,”
ASME J. Eng. Gas Turbines Power
,
129
(
4
), pp.
1028
1034
.10.1115/1.2434344
18.
Zucrow
,
J. M.
, and
Hoffman
,
D. J.
,
1976
,
Gas Dynamics
, Vol.
1
,
Wiley
,
New York
, Chap 1, pp.
63
64
.
19.
Iwatsubo
,
T.
, and
Nishino
,
T.
,
1993
, “
An Experimental Study on the Static and Dynamic Characteristics of Pump Annular Seals With Two Phase Flow
,”
Rotordynamic Instability Problems in High-Performance Turbomachinery
,
NASA
, Lewis Research Center, pp.
49
64
.
20.
Brennen
,
C. E.
,
2005
,
Fundamentals of Multiphase Flows
,
Cambridge University
,
Cambridge, England
, Chap. 2.
21.
Crowe
,
C. T.
, and
Michaelide
,
E. E.
,
2005
,
Multiphase Flow Handbook
,
C. T.
Crowe
, ed.,
CRC
, Boca Raton, FL., Chap. 1.
22.
McAdams
,
W. H.
,
Woods
,
W. K.
, and
Heroman
, Jr.,
L. C.
,
1942
, “
Vaporization Inside Horizontal Tubes, 2: Benzene-Oil Mixtures
,”
Trans. ASME
,
64
, pp.
193
200
. Available at http://130.203.133.150/showciting;jsessionid=38E92D529396CBFB7F22308CB425FA79?cid=11125265
23.
Hassini
,
M. A.
, and
Arghir
,
M.
,
2012
, “
A Simplified Nonlinear Transient Analysis Method for Gas Bearings
,”
ASME J. Tribol.
,
134
(
1
), p.
011704
.10.1115/1.4005772
You do not currently have access to this content.